The field of the invention is dispensers for chemical concentrates, and particularly the dispensing of chemical concentrates at multiple flow rates and different concentrations.
Dispensers of the type concerned with in this invention are disclosed in U.S. Pat. Nos. 5,320,288 and 5,372,310. While the spraying apparatus disclosed in these patents can control the flow of carrier fluid and chemical product it cannot do so in a precise and controlled manner.
U.S. Pat. No. 2,719,704 discloses a valve element 31 with eductor passages 41 and 43. These interconnect with inlet openings 58 and 61.
U.S. Pat. Nos. 2,991,939 and 4,901,923 disclose eductor type dispensers having rotatable discs with various sized apertures for controlling the amount of concentrate being drawn into the water flowing through a nozzle.
A dispenser which dispenses chemical concentrate should have the capability of dispensing the concentration at a low rate such as in the instance where a bottle is to be filled and at a high rate where a bucket is to be filled. In the instance of a bucket fill, it is desirable if both a low and high concentration of chemical concentrate can be provided.
The prior art provides either a rotatable eductor with concentrate flow passages, eductor type dispensers having rotatable discs with various sized apertures, or a sliding open-venturi. It does not provide a dispensing apparatus with both sliding and rotating eductors as well as valving so as to afford different concentrations of chemical concentrate at different flow rates.
In application Ser. No. 09/956,294 filed Sep. 19, 2001, a dispenser for dispensing different concentrations of chemical concentrate into a stream of water from a concentrate container at different flow rates is disclosed. The teachings of this application are incorporated by reference. The disclosed dispenser includes a body member having a through bore with an inlet end adapted to be connected to a source of pressurized water at one end and an outlet at the opposite end connected to the inlet housing. A valve member is slideably positioned in the through bore of the body member. An eductor is slideably and rotatably received in the body member. The eductor is in contact with the valve member and in fluid communication with a source of chemical concentrate. A trigger member is connected to the body member and eductor to cause slideable movement of the eductor. The eductor and valve member are constructed and arranged to provide control of both different concentrations of chemical concentrate and different flow rates of water and chemical concentrate.
The present invention provides an improvement of the dispenser disclosed in Ser. No. 09/956,294 by providing an improved functionality of the previously disclosed dispenser by preventing rotation of the concentration selection members during operation of the device. This is important to the quality of the delivered diluted product, namely to the precise ratio of the concentrate to the carrier stream and the resultant mixture concentration. The previously disclosed design allowed the concentrate selection device to be rotated during the “ON” condition. During this rotation of the concentrate selection members, the flow of concentrated product to the mixing chamber is blocked and then reopened at a new position corresponding with a different product flow rate. If this is allowed to occur during the “ON” condition, the carrier stream/water flowing the diluted concentration of the product in the container to which dispensing is occurring will be incorrect and, as is the case with many such concentrated products, will not function as intended.